The present invention relates to a flavorant composition exhibiting warm/hot, spicy and pungent sensations related to Galangal. More particularly, it relates to a flavorant composition comprising at least one 1xe2x80x2-acetoxychavicol acetate or 1xe2x80x2-acetoxyeugenol acetate derivative. The present invention also relates to food, beverages or healthcare products containing a flavorant composition of the present invention as well as a method of flavoring food, beverages or healthcare products using the flavorant composition.
Hot peppers like red pepper (Capsicum annuum L.)xe2x80x94in Europe also known as Paprikaxe2x80x94and chili pepper (Capsicum frutescens L.) comprise an essential ingredient in a number of Asian and European cuisines. It is well known from Thresh et al., Pharm. J. and Trans. (1876), 7, 21; Micko et al., Z. Nahr. Genussm. (1898), 1, 818 or A. Szallasi, P. M. Blumberg, Adv. Pharmacol. (1993), 24, 123 that Capsaicin is the active ingredient in hot peppers of the plant genus Capsicum. As mentioned in A. Szallasi, Gen. Pharmac. (1994), 25, 223 the oral consumption of hot peppers leads to profuse perspiration which ultimately leads to heat loss. This well established effect, which is known as gustatory sweating, is most probably the reason for the high popularity of hot peppers in countries in hot climates, as well as the flavoring of food.
Capsaicin is one of the most active members of a class of compounds commonly referred to as capsaicinoids, see J. Szolcsanyi in, Handbook of Experimental Pharmacology, A. S. Milton, Ed., Vol. 60, pp. 437-478, Springer, Berlin, (1982). Other well known compounds of this class are Piperine, the active ingredient in black pepper (Piper nigrum L.), see Cazeneuve et al., Bull. Soc. Chim. France. (1877), 27, 291, and Gingerol, the active ingredient in ginger (Zingiber officinale R.).
Galangal (also called galanga, galingale, galangale, calangall) is the name for a member of the monocotyledonus family Zingiberacea. Alpinia officinarium, the smaller Galangal, is native to southern China, while the greater Galangal, Alpinia galanga or Languas galanga, is a larger plant native to Java and Malaya. Alpinia galanga is a stemless perennial herb with fragrant short living flowers. The reddish-brown rhizomes of this plant, having a spicy aroma and a pungent taste somewhere in between pepper and ginger, are used as a spice and especially as a ginger substitute for flavoring foods, e.g. meat, rice or curry. Galangal oleoresin is used as a modifier for ginger, cardamom, allspice, nutmeg etc. with which it blends favorably. The oleoresin remains, however, a rarity and specialty, which is offered by flavor supply houses.
The compounds 1xe2x80x2-acetoxychavicol acetate and 1xe2x80x2-acetoxyeugenol acetate are known compounds. They have been isolated from Alpinia galanga and are described to have anti-tumor activity (see H. Itokawa et al., Planta Medica ((1987), 32-33), to inhibit xanthin oxidase (see T. Noro et al., Chem. Pharm. Bull. (1988), 36, 244) and to have anti-fungal activity (see A. M. Janssen et al., Planta Medica 1985, 507). Furthermore, 1xe2x80x2-acetoxychavicol acetate is described to have anti-ulcer activity (see S. Mitsui et al., Chem. Pharm. Bull. (1976), 24, 2377) and to be a potent inhibitor of the tumor promoter-induced Epstein-Barr virus activation (see A. Kondo et al., Biosci. Biotech. Biochem. (1993), 57,1344). H. Mori et al., Nippon Shokuhin Kagaku Kogaku Kaishi (1995), 42, 989. 1-acetoxychavicol acetate is an aroma constituent of Galanga as determined by GC olfactometry, i.e. they determined only the retronasal aroma by GC sniffing without having tested the trigeminal effect of this constituent.
The present invention provides 1xe2x80x2-acetoxychavicol acetate and 1xe2x80x2-acetoxyeugenol acetate and derivatives thereof which exhibit a strong trigeminal effect which causes a warm/hot, spicy and pungent sensation perceived upon tasting any form of spice which is related to Galangal.
The present invention also provides a method of flavoring food, beverage or healthcare products using the flavorant composition of the present invention as well as the flavored food, beverage or healthcare products.
According to the invention at least one compound selected from the group consisting of 1xe2x80x2-acetoxychavicol acetate, 1xe2x80x2-acetoxyeugenol acetate and related compounds of formula I 
wherein
A=H, OR4 
X=OH, OCOR1 
Y=H, OCOR3 
and
R1, R3=H, branched or unbranched C1-6 alkyl, C2-6 alkenyl, C2-6 alkinyl,
R2=H, branched or unbranched, substituted or unsubstituted C1-6 alkyl, C2-6 alkenyl, C2-6 alkinyl, C3-C6 C6 carbocycle,
R4=branched or unbranched C1-6 alkyl, C2-6 alkenyl, C2-6 alkinyl,
is added to a flavorant acceptable carrier to produce a flavorant composition exhibiting warm/hot, spicy and pungent sensations related to Galangal.
The effect is somewhat similar to those elicited by capsaicin and other capsaicinoids derived from hot peppers, by piperine derived from black pepper, by gingerols derived from ginger and by isothiocyanates derived from mustard. However, all of the latter compounds impart usually long-lasting sensations which are very often undesirable, especially if spicy foods are consumed with more delicately flavored food and/or drink, e.g. with red wine. In contrast, the flavorant composition according to the invention surprisingly produce a pungency of relatively short duration, which makes them ideal for flavoring foods where a lingering effect is undesirable.
In addition, the flavorant compositions of the invention have a warming, alcohol-boosting effect in alcoholic beverages, e.g. making a beverage containing about 15% alcohol taste like one containing about 30% alcohol.
The flavorant composition comprising the compounds of formula I may be used in either enantiomeric form, in any ratio of enantiomers or in racemic form.
The flavorant composition of the invention exhibits Galangal related effects of warm/hot, spicy and pungent sensations to food products, beverages and consumer healthcare products, e.g. mayonnaise, sour cream, onion dip, vegetable dip, potato chip snack, chewing gum, hard candy, mouthwash, toothpaste, etc.
The novel compounds of the flavorant compositions are listed in Table I.
wherein R is H, CH3, CH2CH3, or CH(CH3)2.
All these compounds exhibit the above mentioned warm/hot, spicy and pungent sensations and are preferred. The most preferred compounds for use in flavorant compositions are listed in Table II.
Thus, according to the invention a flavorant composition contains at least one synthetically prepared compound of formula I and a flavorant acceptable carrier and exhibits warm/hot, spicy and pungent sensations related to Galangal. The flavorant compositions may be naturally occurring and are therefore preferred. The compounds of formula I, preferably those of Table I, more preferably those of Table II, might be used to generate the above mentioned effects in a variety of food, beverages or consumer healthcare products, e.g. in hard candy, chewing gum, mayonnaise, sour cream, onion and other vegetable dips, potato chip snack, alcoholic cordial, mouthwash and toothpaste. The compounds of formula I do not suffer the serious disadvantage of lingering hotness nor do they exhibit other negative effects characteristic of lingering food ingredients like capsaicin, gingerol and piperine.
Further, the appropriate compounds for the flavorant composition may be readily prepared by methods known to those skilled in the art. The preferred method for the preparation of compounds of formula I involves the following steps a) to c):
a) A halo-alkane-, alkene-, or alkine of type R2X, where X is a halogen atom and R2 has the above defined meaning, is reacted with magnesium to form a Grignard reagent of type R2MgX. The reaction with magnesium is preferably carried out in tetrahydrofuran (THF), however, other solvents such as diethyl ether may also be used. The ratio of magnesium to halo-alkane-, alkene-, or alkine R2X is preferably from 1 up to about 5 moles of magnesium per mole of R2X, more preferably, from 2 up to 3 moles of magnesium per mole of R2X. The reaction is carried out at a temperature from 10xc2x0 C. up to about 50xc2x0 C., preferably at a temperature from 40xc2x0 C. up to about 50xc2x0 C. Temperatures lower than 20xc2x0 C. give rise to a reaction which is too slow to be economical. Temperatures higher than 50xc2x0 C. give rise to side reactions causing an undue lowering of yield of product.
b) The Grignard reagent of type R2MgX produced in step a) is then reacted with a benzaldehyde derivative. The mole ratio of R2X prepared in step
a) to benzaldehyde is from about 2 up to about 6 moles of R2X used per mole benzaldehyde derivative, more preferably from 3 up to 5 moles of R2X per mole of benzaldehyde derivative. The aldehyde may be added to the Grignard reagent in neat form or dissolved in an inert solvent such as tetrahydrofuran and diethyl ether, most preferably the benzaldehyde derivative is added in the form of a tetrahydrofuran solution. The reaction is carried out at a temperature of between xe2x88x9220xc2x0 and up to 50xc2x0, preferably at about 30xc2x0 C. The reaction mixture may be hydrolyzed with mineral acid, e.g. hydrochloric acid, sulfuric acid, or with saturated ammonium salt solutions, e.g. ammonium chloride or ammonium sulfate. Most preferably ammonium chloride is used for the hydrolysis. The Grignard reaction products may be purified by a chromatography method or may be used in crude form for the next step.
c) The Grignard addition products are finally acylated to give the desired compounds of formula I. The acylation may be carried out in a tertiary amine such as pyridine, triethyl amine, preferably pyridine. Most preferably pyridine is used in combination with a catalytic amount of 4-N,N-dimethylaminopyridine. As acylating agents acid chlorides or acid anhydrides may be used, preferably the acid anhydrides are used.
The compounds of formula I may preferably be purified by chromatography or by crystallization methods.
An alternative method of preparing compounds of formula I involves the following steps:
a) An alkyl-, alkenyl-, or alkinyl metal derivative of type R2M, where R2 has the above defined meaning and M represents an alkali metal (e.g. Li, Na, K), is reacted with the corresponding benzaldehyde derivative. Alkyl-, alkenyl-, or alkinyl metal derivative of type R2M are commercially available or may be readily prepared by methods known to those skilled in the art. The ratio of R2M to benzaldehyde derivative is preferably from 2 up to 5 moles of R2M per mole benzaldehyde derivative. The reaction is carried out in an inert solvent such as tetrahydrofuran (THF), diethyl ether, benzene and xylenes. The aldehyde may be added to the R2M reagent in neat form or dissolved in an inert solvent such as tetrahydrofuran and diethyl ether, most preferably the benzaldehyde derivatives are added in the form of a tetrahydrofuran solution. The reaction is carried out at a temperature of between xe2x88x9220xc2x0 and 50xc2x0, preferably at about 30xc2x0 C. The reaction mixture may be hydrolyzed with mineral acid, e.g. hydrochloric acid or sulfuric acid, or with saturated ammonium salt solutions, e.g. ammonium chloride or ammonium sulfate. Most preferably ammonium chloride is used for the hydrolysis. The reaction products may be purified by chromatography or may be used in crude form for the next step.
b) The addition products of R2M to the benzaldehyde derivatives are finally acylated to give the desired compounds of formula I. The acylation may be carried out in a tertiary amine such as pyridine, triethyl amine, preferably pyridine is used as the solvent, most preferably pyridine and a catalytic amount of 4-N,N-dimethylaminopyridine is used. As acylating agents acid chlorides or acid anhydrides may be used, preferably the acid anhydrides are used.
The products of formula I may be purified by chromatography or by crystallization.